Synopsis
Diagnose childhood constipation positively, detect impaction and organic red flags, then combine complete disimpaction, sustained laxative maintenance and non-punitive toileting support until bowel function is reliably restored.
- Diagnose idiopathic constipation from history and examination: fewer than three complete stools weekly, large hard stool, painful defecation, withholding, overflow soiling or a palpable mass.
- Ask age at onset and meconium timing before accepting a functional diagnosis; neonatal features or neurological and anatomical abnormalities are red flags.
- First-line assessment does not require routine abdominal radiography, ultrasound, transit study or digital rectal examination in primary care.
- Assess for faecal impaction from overflow soiling, abdominal or rectal mass and symptom pattern before starting maintenance.
- First-line disimpaction is oral macrogol 3350 plus electrolytes using the age-specific escalating NICE schedule, warning that soiling and pain may temporarily increase.
- If macrogol alone fails, add a stimulant laxative; use rectal treatment only after oral regimens fail and with informed consent and specialist guidance.
- After clearance, continue macrogol maintenance, adjust to regular soft painless stool and continue for weeks after habit is established, tapering gradually rather than stopping abruptly.
- Combine laxative treatment with scheduled relaxed toilet sitting after meals, foot support, rewards for the routine rather than stool output and school access.
- Do not rely on fibre and fluid alone for impaction and never punish overflow soiling.
Key red flags
Constipation from birth or first weeks, delayed meconium beyond 48 hours in a term baby or ribbon stool suggests Hirschsprung disease or congenital anatomy.
Bilious vomiting with distension, fever, bloody diarrhoea or shock raises obstruction or Hirschsprung-associated enterocolitis.
Abnormal anus, sacral dimple with neurological features, absent reflexes, leg weakness or abnormal gait suggests spinal or anorectal disease.
Faltering growth, severe abdominal distension, thyroid features or unexplained systemic illness requires targeted organic assessment.
Extreme distress, anal injury, sexualised behaviour or an inconsistent history requires sensitive safeguarding consideration.
Soiling is usually overflow and not deliberate; punitive responses increase withholding, shame and treatment failure.
Investigation priorities
Make a positive idiopathic diagnosis, identify impaction and screen neonatal, growth, neurological and anatomical red flags.
Management branches
Constipation or soiling is reported during clinical assessment.
- Ask onset, meconium, stool, withholding, pain, soiling, urinary and psychosocial history.
- Examine growth, abdomen and relevant neurological or anorectal features.
- Refer red flags and assess all other children for impaction.
Impaction has cleared or the child was not impacted.
- Continue daily macrogol, titrating to soft painless regular stool.
- Add supported post-meal sitting, footstool, non-punitive rewards and a school toilet plan.
- Continue for weeks after habit is stable and taper gradually with relapse instructions.